SAN FRANCISCO (KGO/CNN) – The animal rights group PETA is fighting to prove that monkeys can sue for copyright infringement.

The case stems from some famous “selfie” pictures taken by a monkey, and it has now reached a federal appeals court.

Attorney David Schwartz appeared in court Wednesday on behalf of the “appellant” – a person making an appeal, except when it’s not a person.

“A monkey just walked into federal court and sued for copyright infringement,” said Andrew Dhuey, the photographer’s attorney. “It sounds like I’m setting up a punchline, but it really just happened.”

The monkey, “Naruto,” is technically still in Indonesia, where the selfie was taken. Naruto picked up photographer David Slater’s camera and noticed that pushing the button changed the reflection in the lens.

The animal rights group claims Naruto is the true author of the photo and entitled to royalties from Slater’s book.

It’s a new take on the U.S. Copyright Act. PETA says it’s a broader definition of the word “author,” much the way courts have broadened other words.

“Spouses reflected a man and a woman in a marriage,” Schwartz said, “and that is no longer a case that one would defend.”

One of the judges asked if there was a similar Supreme Court holding that man and monkey are the same. There’s not, but the attorneys countered with the Citizens United ruling, which stated corporations are persons under the law.

“Monkey see, monkey sue will not do in federal court,” Dhuey argued.

The defendants’ lawyers said the case has been tough on their clients, and that’s why they’re asking the court to make PETA pay what could amount to $250,000 in attorneys’ fees.

“We’ve been going on for almost two years,” Dhuey said. “It’s totally unfair.”

Peta says what’s unfair is what humans have done to these monkeys.

“They are in danger of extinction,” Kerr said. “Their numbers have decreased 90 percent over the last 25 years, their habitat is being encroached on by humans, they’re being killed for bush meat.”

PETA said it would put the royalties toward conservation efforts.

The defense only wishes they could ask Naruto about all this.

“You’re not required to be in court, but when you don’t show up, it’s like Naruto doesn’t even care,” Dhuey said.